It's only a matter of time

[cycletrak9]

I need some help with a problem.

My trusty Casio black plastic [nylon?] watch has given up the ghost after a mere 15 years of devoted service -broken case.

I'm picking up a replacement from Argos in the morning, cost £8.38 but I'll need to set the time. I'm something of a nerd about accurate time keeping and I wondered which of the available sources gives the most accurate Greenwich time signal. I'm  great radio fan and listen on a variety of sources [DAB, analogue, TV both satellite and terrestrial] and I've noticed that there are time lags between the various transmissions. Does anybody know which is closest to the "right time"?

I tend to use the Casio as my reference point for setting my other watches, including a couple of vintage wind up pieces. Can someone enlighten me?

[dannyboy]

watch has given up the ghost after a mere 15 years of devoted service - they don't make them like they used to

I am not sure which of the available sources would be the most accurate, but as an aside, I did read in the paper the other day that there will be one 'leap' second added at 23:59:59 tomorrow night!

[jthjth]

Try the website time.is

https://time.is/about explains how it gets its time.

[keithfre]

Steam radio will give you an accurate time signal, apart from the tiny amount of time it takes the signal travelling at the speed of light to reach the set.

[Sprintex]

Can't beat using the source

https://greenwichmeantime.com/


Paul

[jthjth]

Sadly, radio today is unlikely to give an accurate time signal. Now that the distribution links are digital, the time delays from the source of the "pips" can be quite variable depending on the route to the transmitter. (Even if the final hop from the transmitter to the radio is analogue FM). A couple of decades ago the distribution delays were minimal, but that cannot be relied upon anymore. DAB is even worse, as it takes an additional time for your radio to decode the signal, and this varies between makes. Time on a computer can be very accurate, as there is a protocol called NTP that measures the delays on the link (e.g. internet connection) and compensates accordingly. Radio clocks that receive either the signal from Anthorn in Cumbria or Frankfurt in Germany can be very accurate, though I do find some of the cheap ones can be a second out in their display. GPS time is very accurate (to nano seconds), but again you can lose accuracy in what is actually displayed on something that is really intended to be a satnav.

I did once see the equipment that generated the time pips in the basement of Bush House for the BBC. It was in the early days of GPS. Three GPS receivers and a 60 kHz Rugby MSF receiver for "patriotic" reasons. Since then Rugby radio has turned into a housing estate and the transmitter moved to Cumbria, feeding a rather inadequate antenna. This is why many radio clocks have become less good at keeping lock (unless you have a Frankfurt one from Aldi/Lidl....)

[Bealman]

It's all relative..... doesn't everyone know it's 10.17am on Saturday? 

[daffy]

Full details of the NPL Time Service system here, that makes sure a computer shows accurate time data by reference to a reliable time source:

http://www.npl.co.uk/upload/pdf/tts_user_guide.pdf

[D1042 Western Princess]

When I was working as a Guard (OK, Train Manager, in 'Newspeak) on First Great Western I had two watches, both (officially) 'radio controlled by a broadcast 'time signal' and therefore (in theory) should have been showing exactly the same time.
In practise they sometimes showed up to 30 seconds difference.
Given I live in Swindon, where you'd expect FGW to show the correct time, if no where else on their system, one watch reads (at the time of writing)
05.50.17  and the other 05.50.45 

How does anyone define the 'right time' to the second?

[cycletrak9]

Thanks everyone

It seems that, as with so many things, you pays your money and you takes your choice.

I can't imagine that I'll ever need to worry about 30 seconds either way but it was good to have the benefit of your collected wisdom.

[oscar]

According to time.is, my laptop is 0.2 of a second out!

[daffy]

@oscar, I think it's time to panic!

With a leap second being added tonight to global clocks you will be totally out of step with mankind this time tomorrow.

[Bealman]

Except of course for my tongue in cheek remark. 

However, time moves on, and we are just a couple of hours away from the new year here.

All the best for 2017, everyone!

Back on topic, cycletrak9, I do believe our local electronics mag published a design for a GPS clock a year or so ago. I'll try and dig it out. 

George

[oscar]

Daffy, at 77 I'm well out of step with the modern world! 

[daffy]

Daffy, at 77 I'm well out of step with the modern world! 

i know exactly what you mean Oscar, and I'm only 64!